JPS5857206B2 - oil water separation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil/water separation system used in an oil drain treatment system in a radioactive waste treatment facility in a nuclear power plant.

A conventional oil-water separation system for an oil drain in a radioactive waste treatment facility in a nuclear power plant will be described with reference to FIG.

Oil drain generated within a nuclear power plant is collected in an oil drain sump tank 1, and is sent to an oil separation tank 3 by a sump pump 2.

The oil drain sent to the oil separation tank 3 is separated into oil and moisture here.

The separated oil is sent to an oil drain storage tank 4, measured in an oil drain measuring tank 5, and packed into a drum can 6 to be stored as radioactive waste.

After the water is sent to the oil drain collection tank 7, it is sent to the filter 9 by the oil drain collection pump 8 to remove foreign substances, and then sent to the oil absorption tank 10, where the oil content in the water is completely removed. Sample tank 10 after being removed
It is a system that releases after being sent to a.

However, in the oil separation tank used in conventional systems, the inflow speed of the incoming oil drain is reduced by an internal preliminary tank, and the overflow is allowed to flow into the main tank. Because the structure is such that water is separated from the upper part of the oil-water interface and oil is removed from the lower part, it takes time to separate the oil and water by specific gravity, and the interface level changes depending on the ratio of oil and water. There is a great possibility that water or oil may be mixed into the removed oil or removed water.

If water is mixed into the removed oil, the amount of drums stored as radioactive waste will increase, and if a large amount of oil is mixed into the removed water, it will be poured into the oil absorption tank for later treatment. The load increases, and the internal elements of the oil absorption tank must be replaced more frequently.

Therefore, by taking this point into consideration, the processing capacity of the oil absorption tank must be increased.

The present invention takes into consideration the various disadvantages of the oil absorption tank described above, and the first objective is to obtain an oil-water separation system that separates oil without containing water and reduces the amount of radioactive waste. be.

The second objective is to separate the oil contained in water as little as possible and evenly, reducing the load on the oil absorption tank.
The object of the present invention is to obtain a system that reduces the capacity of an oil absorption tank.

In the following - the invention will be explained with reference to the drawings of exemplary embodiments.

FIG. 2 shows an oil drain treatment system using the oil/water separation system of the present invention.

The oil drain sump tank 11 is a tank used to collect oil drain generated within a nuclear power plant.

A sump pump 12 is installed in this oil drain sump tank 11 and is used to convey collected oil drain to a cooling tank 13.

The cooling tank 13 is a tank for storing oil drain sent by the sump pump 12 while the oil drain is cooled down to a certain temperature or lower by a circulation pump 14 and a cooling unit attached to the cooling tank 13.

Further, a level meter 16 is installed in the cooling tank 13 to control the circulation pump 14 and the cooling oil drain discharge pump 15 according to level fluctuations within the tank.

Furthermore, a thermometer 17 is attached to measure the degree of cooling of the oil drain in the tank and to measure the cooling unit side and the cooling oil drain discharge pump 15 side.

The circulation pump 14 is a pump used to cool the oil drain in the cooling tank via the heat exchanger 18. heat exchange between the cooled refrigerant and the circulating oil drain.

That is, the heat exchanger 18, the refrigerator 19, the cooling tower pump 20, and the cooling tower 21 constitute a cooling unit.

The cooling oil drain discharge pump 15 is a pump used to flow the cooled oil drain in the cooling tank 13 to a rotary filter 22 equipped with an automatic backwash mechanism provided downstream of the pump.

Note that 14a is a circulation pump main valve, and 15a is an oil drain discharge pump main valve.

This rotary filter 22 captures water (ice pieces) that have turned into fine ice from the oil drain sent by the cooling oil drain discharge pump 15, and discharges the captured ice pieces using an automatic backwash mechanism. It's a great opportunity.

Further, a differential pressure gauge 23 is installed to measure the pressure at the entrance and exit of the rotary filter 22.

This is a backwash valve 2 that is installed in the branch line 24 when the state of ice fragment capture in the rotary filter 22 is detected and the value exceeds a set value.
5 and the captured ice pieces are transferred to this branch line 24.
This is used for backwashing and discharging the oil to the oil drain collection tank 26 installed in the tank.

The line 27 is provided with an oil drain storage tank 28 .

This is a tank that stores oil from which ice pieces have been removed by the rotary filter 22.

A drum can 30 used for storing the stored oil as radioactive waste is installed downstream of the oil drain storage tank 28 via a measuring tank 29 for measuring the stored oil.

The oil drain collection tank 26 is a tank that collects the ice chips that have been backwashed from the rotary filter 22 and thaws the ice chips in water. , a filter 32, an oil absorption tank 33, and a sample tank 34 are installed in series.

That is, the oil drain collection pump 31 transports the water thawed in the oil drain collection tank 26 to the filter 42.

The filter 32 is used to remove foreign substances such as crud contained in the water sent by the oil drain collection pump 31.

Further, the oil absorption tank 33 is used to completely remove oil contained in the water from which foreign substances have been removed by the filter 32, and the sample tank 34 is used to remove foreign substances with the filter 32 and remove oil with the oil absorption tank 33. When the completely removed water is released, it is used as a reserve for sampling whether the water can be released.

As shown in FIG. 3, the rotary filter 22 used in this system includes a drive motor 51 for rotation, a reducer 52 connected to the motor 51 to reduce the rotation of the motor 51, and a reducer 52 for reducing the rotation speed. It consists of a shaft 54 that transmits the rotational speed to the drum 53, and a media section 55 that is installed on the drum 53 and captures ice chips.

Further, a gland packing 56 is provided on the outer wall of the shaft 54, which is used to prevent the oil drain inside the filter from leaking to the outside.

In addition, the V seal 57 used to seal the primary side and the secondary side of the rotary filter machine 220 is attached to the drum 53 and the casing 5.
It will be installed between 8 rooms.

Inside the filter, as shown in FIG. 4, which is a side view of FIG. 3, the casing 58 has a backwash port 59 required for backwashing.
and a backwash space 60 are provided.

A media section 55 that is attached to the rotary filter 22 and that captures small pieces of ice is set by a retainer 61 as shown in FIG.

This media section 55 has a disk shape with a tapered hole 62, and in order to effectively perform backwashing, the smaller diameter of the tapered hole 62 is connected to the primary side of the rotary filter 22 (the drum 53). The tapered hole 62 with the larger diameter is set on the secondary side of the rotary filter 22 (on the inside of the drum 53).

Next, the effect will be explained.

An oil drain treatment system with an oil/water separation system configured in this way separates oil drain generated within a nuclear power plant into oil and water.The oil is stored in the nuclear power plant as radioactive waste, and the water is stored as foreign matter. This is a system that completely removes and releases the

Oil drain generated within a nuclear power plant is collected in an oil drain sump tank 11 and is sent to a cooling tank 13 by a sump pump 12 installed in the oil drain sump tank 11.

A level meter 16 for measuring the liquid level in the tank and a thermometer 17 for measuring the temperature inside the tank are installed in the cooling tank 13, and the discharge from the tank and the cooling state are controlled.

The oil drain stored in the cooling tank 13 is circulated by the circulation pump 14 in order to freeze the moisture contained therein and turn it into fine ice, while being circulated through the heat exchanger 18, the refrigerator 19, the cooling tower pump 20, and the cooling tower 21. It is cooled by a cooling unit consisting of.

The operation of the circulation pump 14 and the cooling unit, the cooling oil drain discharge pump 15 and the rotary filter 22 are controlled by the set value of the thermometer 17 attached to the cooling tank 13 and the state of the level meter 16. There is.

The temperature setting value for the operation of the circulation pump 14 and cooling unit is to operate when the temperature reaches approximately -15°C or higher, and to operate at approximately -30°C.
It will stop when the following occurs.

Also, the temperature settings for the operation of the cooling oil drain discharge pump 15 and the rotary filter 22 depend on the length of the piping, etc., but they operate when the temperature drops to about -10°C or lower, and when the temperature drops to about -10°C or higher. It is stopped.

The circulation pump 14 and the cooling oil drain discharge pump 15 are operated by the circulation pump main valve 14a and the discharge pump main valve 15a.
adjusted by.

Only water is turned into fine ice by the cooling unit, and the oil drain stored in the cooling tank 13 is sent to the rotary filter 22 by the cooling oil drain discharge pump 15.

In the oil drain sent to the rotary filter 22, only the moisture that has been turned into fine ice is captured in the media section 55, and the oil content is sent to the oil drain storage tank 28.

The oil drain sent to the oil drain storage tank 28 is sent to the oil drain measuring tank 29 at appropriate times, is measured, is packed into a drum can 30, and is stored in the nuclear power plant as radioactive waste.

On the other hand, as the amount of ice chips captured in the media section 55 increases, the differential pressure of the rotary filter 22 increases, and this differential pressure is detected by the differential pressure gauge 23, and this value is detected by the differential pressure gauge 23. Setting value (
When it reaches about 0.3 to 0.41<g/crA), the backwash valve 25 is opened.

When the backwash valve 25 is opened, the ice pieces trapped in the media section 55 are discharged into the oil drain collection tank 26 due to internal pressure.

The backwash valve 25 is closed when the differential pressure reaches approximately 0.1 ky/crA.

The ice chips collected in the oil drain collection tank 26 are thawed here and sent to the filter 32 by the oil drain collection pump 31, where parts such as crud are removed.
The oil is sent to the oil absorption tank 33.

The oil contained in the oil absorption tank 33 is completely removed.

The water from which oil has been completely removed after passing through the oil absorption tank 33 is sent to a sample tank 34, where the water is sampled.
If there is no abnormality, it is released from a release canal (not shown).

As explained above, the oil/water separation system of the present invention can completely remove water by cooling the oil drain and turning it into fine ice.Therefore, there is no water content at all in the oil drain, which is stored as radioactive waste. can only reduce the amount of radioactive waste.

Furthermore, since the entire system is a continuous system and uniform treatment is possible, the load on the oil drain collection tank, filter, and oil absorption tank is reduced, and the overall capacity can be reduced.

Further, when the water is cooled and turned into fine ice, the exposed foreign matter in the oil drain is solidified and concentrated and removed by a filter, thereby reducing the radiation dose of the oil drain, which becomes radioactive waste.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a conventional oil drain oil/water separation system, FIG. 2 is a system diagram of an oil drain oil/water separation system showing an embodiment of the oil/water separation system of the present invention, and FIG.
The figure is a partially sectional front view of the rotary filter used in the oil/water separation system in Figure 2, Figure 4 is a side view of the rotary filter in Figure 3, and Figure 5 is the rotary filter used in the oil/water separation system. FIG. 3 is a sectional view showing details of the media section of the rotary filter shown in the figure. 13... Cooling tank, 18... Heat exchanger, 22... Rotary filter, 26...
Oil drain collection link, 28...Oil drain storage tank, 3o...°゛Drum can 32...
...Filter, 33...Oil absorption tank, 34...
・Sample tank.

Claims (1)

[Claims] 1 Consists of a cooling tank that receives the oil-water mixture, a cooling unit that is installed in this cooling tank and that circulates and cools the liquid in the cooling tank, and a rotary filter that is also connected to the cooling tank. The rotary filter includes a cylindrical filtration member, a drive mechanism that rotates the filtration member around a cylindrical shaft, an introduction path for an oil-water mixture that communicates between the cooling tank and the inside of the filtration member, and the An oil/water separation system comprising an oil discharge path provided in an outer compartment of a filter member, and a water particle discharge mechanism provided in communication with the inner side of the filter member.